Burner for solid fuel



July 3, 1928. 7 1,675,548

c. H. HALL ET AL BURNER FOR SOLID FUEL Filed July 1925 2 Sheets-Sheet lA TTORNEY C. H. HALL El AL July 3, 1928.

BURNER FOR SOLID FUEL 2 Sheets-Sheet Filed July 9, 1925 A TTORNEYPatented July 3, 1928.

UNITED STATES PATENT OFFICE.

CORTICE H. HALL, OF IE'A'IERSON, NEW JERSEY, AND WILLIAM LLOYD, OFHAZLETQIT, PENNSYLVANIA, ASSIGNORS TO DOMESTIC STOKER COMPANY, OF NEWYORK, 11'. Y.,

A CORPORATION OF DELAWARE.

BURNER non SOLID FUEL.

-App1icatioiffi1ed July 9, 1925. Serial No. 42,347.

This invention relates generally to the construction of burners fordomestic furnaces and more particularly to burners of the under-feed,mechanically-stoked type for use with solid fuel.

In the operation of domestic or household furnaces of the under-feedburner type in which solid fuel is fed to the lower extremity of theburner through the action of a screw conveyor, considerable diflicultyis found in practice in causing the upper extremity of the column offuel rising through the burner to distribute itself in a uniformly evenlayer on the grate structure.

Difliculties in manufacture have also been encountered in casting agrate or burner plate of an annular and frusto-conical for-.

mation most suitable for use with underfeed burners of thetype referredto.

.A general object of this invention is to eliminate the objections anddifficulties referred to, and to provide a burner structure in which thefuel will be automatically dis-- tributed in a uniform layer forcorrespondingly uniform combustion on the burner plate. Another objectof the invention is to provide a burner plate or grate structure whichcan be inexpensively manufactured, and, in general, to provide a burnercharacterized by simplicity of structure, adaptability to functioninfurnaces of various sizes, and to operate effectively and efficientlywith a minimum degree of attention.

The invention includes a fuel distributing member forming part of the.burner structure. The fuel distributing member is arranged to receivefuel from the delivery terminal of a screw conveyor and to direct the- 0received fuel upwardly to resent a uniformly level combustion sur ace atthe upper end of the burner. In order to provide the desired uniformityof surfacelevel, the

fuel distributing member is provided. with baflle or directing surfacesarranged to counteract a tendencyof the screwv conveyor to bank thematerial atone side of the burner and thereby interfere with a desireduniformityof combustion.

Another feature of the invention resides in a perforated burner plateorgrate having an annular frusto-conical formation and formed in sectionsto facilitate the operation of casting. i

Still another feature of the invention resides in the provision of meansfor adapting the burner to furnace structures having firepot chambers ofdifferent heights and Widths.

Other features of the invention will be hereinafter referred to. I

In the drawings, in which a preferred embodiment of the invention hasbeen selected for illustration,

Figure 1 is a view partly in plan and partly in horizontal section of asolid-fuel burner embodying the invention and taken on the line 11 ofFigure 2.

Figure 2 is a View in vertical longitudinal section of the burner shownin Figure 1.

Figure 3 is a view in vertical section taken on the line 33 of Figure 2.

Figure 4 is a detail sectional view taken on the line 44 of Figure 2.

Referring to the drawings for a more detailed description of theinvention, a burner of the under-feed solid-fuel type is shown in whicha hollow framework or casing 10.

opens upwardly and isprovided, at one side and in a lower portionthereof with a fuel inlet port or opening 11 through which is passed apipe or con uit 12- in which a fuel feeding device of the screw conveyortype 13 is mounted for operation.

The fuel or feed pipe 12 delivers into an elbow-shaped conduit member 14which opens upwardly into an annular fuel conducting member 15.

The fuel conducting member 15 in turn delivers fuel upwardly into anannular burner plate or grate member 16 having expanding or flaringwalls terminating in the orizontal plane of a horizontal flange mem,

ber 17 :formed on an annular burner plate supporting member 18.

The lower or tapering end of the burner plate, member 16 is received ina seat or recess 19 formed for the purpose in the up-' 7 conduit 25through which a draft of air may be forced by a blower of any suitableform to assist in the combustion of fuel in the burner. It will be seenthat air passing through the conduit 25 takes the form of an annularstream in surrounding or enclosing relation to the feed pipe 12 and thatthe air stream passes into the chamber 26 formed by the casing 10 fromwhence it passes through openings or ports 27 provided in the fuelconducting member 15 and corre sponding ports or orifices 28 in theburner plate 16, into the mass of fuel contained within these portionsof the burner. The combustion of the fuel which takes place at andadjacent the upper surface of the bed of fuel resting in the hollowburner plate 16 and on the flange 17 of the burner plate support, is, aswill be seen, facilitated or enhanced by the draft of air forced intoand through the fuel bed from beneath. The conducting member 15 and theburner plate 16 combine to form the grate of the burner. The term grateis used in the appended claims to include both of these members.

Al feature of the invention herein described resides in the provision ofmeans for insuring that the fuel rising through the conducting member 15and the burner plate 16 will distribute itself in a uniform and levellayer at the area in which combustion takes place. The means adopted forperforming this important function takes the form of baflie or directingsurfaces 29 and 30 formed on the inner surface of the fuel conductingmember 15 in the lateral surface thereof against which fuel emergingfrom the elbow-shaped member 14 is forced by the lateralthrow of theterminal portion of the helical feed screw 13. The baflling or directingaction of the specially formed portions 29 and 30 is such that thetendency of the fuel to rise to a higher level at that side of theburner plate construction is counteracted with the result that when thefuel mass arrives at the upper portion of the flaring burner plate itdistributes itself in a uniformly level layer which results in acorrespondingly uniform zone of combustion at the top of the burnerstructure. The fuel directing portions 29 and 30 of the fuel conductingmember 15 constitute simple, upward extensions of the substan-- portionsthus provided restrict the movement of fuel against the adjacent flaringwall surfaces 52. This action prevents the building up of an abnormallevel of fuel at one side of the burner through the action of the screwconveyor, the substantially vertical deflecting areas being so locatedas to offset the lateral drift of the material due to the conveyoraction.

Fig. 4 of the drawings shows the height of the upstanding lip at thepoint 30 (Fig. 2), the dotted line marked A in Fig. 4 being areproduction of the section at A in Fig. 2 for purposes of comparison.

Another feature of the invention resides in the construction of theburner plate .16. In order to facilitate the production of burner platesof the formation and type shown the burner plate structure is cast in aplurality of sections, for example, six,

as is indicated in Figure 1 of the drawing. This feature contributesmaterially. to theproduction of the burner plate members at a low costsince the converging air passages 28 provided in the burner plate can beformed in a casting operation thereby eliminating the expense ofdrilling or other cutting operations performed subsequent to and inaddition to the casting operation in which the plate is itself formed.The direction of the orifices 28 which is substantially perpendicular tothe tangent to the arc of curvature of the plate 16 rendersit impossibleto cast the burner plate structure in the form of a one-piece annularmember as will be seen. The sectional structure accordingly enables theburner plate device to be produced by a relatively inexpensive castingoperation.

In order to provide for the removal of accumulations of dust or fineashes from the chamber 26 withinthe casing 10 as required. a series ofclean out ports or openings 31 are provided in the floor member 32 ofthe casing 10. The openings 31 are normally covered by a closure plate33 pivoted on a central downwardly projecting boss 34 formed on thefloor plate 32., The closure plate 33 is provided with. openings 35which through the operation of a link 36 and manually operable handlemember 37 can be moved into or out of register with the cor respondingports 31 in the floor member 32; A stop member50 is provided to limitthe movement of the closure plate 33 in one direction. When the openingsare brought: into register it will be seen that the air draft passinginto the chamber 26 through the conduit 25 will blow the accumulated(lust through the openings 31 from the chamber 26 and thereby accomplishthe desired cleaning out operation.

In order to adjust the burner structure to different elevations requiredin different furnaces, the rearmost portion of the main frame member orcasing 10 is provided with a flange or bracket member 38 having astepped formation 39 along its vertical rearward edge. A hook-shapedsupport-engaging member 40 is also provided with a stepped formation 41arranged to engage the stepped edge 39 of the flange 38 at differentsteps of the length of the flange 38. It will be seen that by thisstructure the flange 38 can be placed at different elevations along thevertical forward edge of the member 40 and locked or attached securelythereto by means of a screw 42 passing through the member 40 into -'.theflange 38.

The member 40 is provided at its upper end with a hook or bill 43 and atits lower extremity with a concave seat 44 so that the hook can beapplied to a horizontal bar 45 of a supporting bracket or standard 46either at the upper hook extremity 43 or the lower recessed portion 44to thereby provide a considerable difference in the elevation of theburner structure as a whole.

To further adapt the burner structure to furnace chambers of differentsizes, provision is made fon varying the lateral or diametrical area ofthe upper surface of the burner structure. This is accomplished by theprovision of removable ring members 4-7 which are provided with lugs 48adapted to fit into corresponding recesses 49 formed in the enclosedring or flange 17 of the burner structure. It will be seen that one ormore rings may thus be provided to in crease the area of the fire pottop to the desired size, it being necessary merely to provide an annularpassage which may be of relatively small width, between the outer edgeof the outermost ring and the inner wall of the furnabe structurethrough which ashes and clinkers remaining when combustion of the fuelhasbeen completed may fall from the outer edge of the flange 17 oroutermost ring.

What We claim is 1. In a solid fuel burner of the underfeed type, anupwardly flaring annular grate, a feed conduit having a horizontalportion and an upwardly directed portion communicating'with the lowerend of the grate, a screw in said conduit for forcing fuel through saidconduit and over the ,in-

'terior of thegrate, the lower portion of said grate being provided onthe interior thereof, at the side at which the conveyer tends to conveyfuel most rapidly, with-an;

upstanding lip adapted to retard the passage of fuel over the grate onthat side and thus produce a level combustion surface at the top of saidgrate.

2. In a solid fuel burner of the underfeed type, an upwardly flaringannular grate, a feed conduit having a horizontal portion and anupwardly directed portion communicating With the lower end of the grate,a screw in said conduit for forcing fuel through said conduit and overthe interior of the grate, the interior of the lower portion of saidgrate at the side at which the conveyer tends to convey fuel mostrapidly being provided with a fuel retarding surface whereby a levelcombustion surface at the top of the grate is attained.

Signed at New York, in the county and State of New York, this 1st day ofJuly,

CORTICE H. HALL. WILLIAM LLOYD.

